The Study On The Mechanism Of Hand-motor Function In Patients After Stroke:a Combination Of VBM And ReHo

Objective:To observe the relationship between the structural and functional changes of motor-relate brain areas and the level of hand-motor recovery in patients whose after stroke through the mean which combines VBM (voxel-based morphometry) with ReHo (Regional homogeneity) in rs-fMRI. Furthermore, we may disclose the basis of possible mechanism of hand-motor recovery in patients after stroke.Methods:We choose ReHo in rs-fMRI and Gray matter density in VBM as indicators to finish this study.13 patients (11 males,2 females) after lateral ischemic subcortical stroke are recruited as experiment group in which all patients accept standardized therapies, assessments of Fugl-Meyer in hand scales when 20 days and 3 months after stroke and MRI scans at the same time as the assessments done.12 healthy volunteers (10 males,2 females) are recruited as control group in which all volunteers only process the same MRI scans as patients does once. All imaging data are analysed by SPM8 in which we choose M1, PMC, SMA and CMA as the ROIs (Region of Interest) to detect dynamic changes of indicators we choose in patients after stroke and the difference in patients to control group. In order to analyse correlation between indicators and motor function scales we use the test of spearman rank correlation.Results:1. The assessments of Fugl-Meyer in hand scales of the start of being hospitalized are significant higher than the post-therapeutic (P<0.01).2. Gray matter density in VBM of experiment group 3 months later is lower than it in control group, but have no significant difference when 20 days compared with the control group. After the experiment group accepting standardized therapies, however,the gray matter density have lower than before.3. The ReHo of the patients in the ROI were higher than the control at any time, and the ReHo of the patients are lower at the start of being hospitalized than 3 months later in the M1 (primary motor cortex), PM (premotor area),conversely in the SMA (supplementary motor area) and CMA (cingulated motor areas).4. Early stroke, the correlation coefficient between VBM and Fugl-Meyer scores is not significant (P>0.05), and the correlation values (Ml vs Fugl-Meyer scores, PM vs Fugl-Meyer scores, SMA vs Fugl-Meyer scores, CMA vs Fugl-Meyer scores) are 0.439,0.386,0.398,0.468; After the experiment group accepting standardized therapies, the correlation coefficient between VBM and Fugl-Meyer scores is significant (P<0.05), and the correlation values (M1 vs Fugl-Meyer scores, PM vs Fugl-Meyer scores, SMA vs Fugl-Meyer scores, CMA vs Fugl-Meyer scores)are 0.736,0.795,0.594 and 0.668. The correlation coefficient between the VBM values changes in the M1 (primary motor cortex), PM (premotor area), SMA (supplementary motor area) and CMA (cingulated motor areas) and the Fugl-Meyer (hand and wrist) value changes are -0.590、-0.635、-0.778、-0.809, The correlation coefficient is significant(p< 0.05).5. Whenever, the correlation coefficient between ReHo values and Fugl-Meyer scores is significant (P<0.05). Before accepting therapies,the correlation values of patients (M1 vs Fugl-Meyer scores, PM vs Fugl-Meyer scores) are 0.663,0.569, which means positive correlation, and the correlation values (SMA vs Fugl-Meyer scores, CMA vs Fugl-Meyer scores) are -0.685,-0.569, which means negative correlation in the patients, and the correlation coefficient are significant (P<0.05).After accepting therapies,the correlation values of patients (M1 vs Fugl-Meyer scores, PM vs Fugl-Meyer scores) are 0.848,0.731, which means positive correlation, and the correlation values (SMA vs Fugl-Meyer scores, CMA vs Fugl-Meyer scores) are -0.730,-0.730, which means negative correlation in the patients, and the correlation coefficient are significant (P<0.05). Finally, the correlation coefficient between the ReHo values changes in the M1 (primary motor cortex), PM (premotor area),,SMA (supplementary motor area) and CMA (cingulated motor areas) and the Fugl-Meyer (hand and wrist) vanlue changes are 0.721,0.755,0.614,0.607, and the correlation coefficient are significant (P<0.05)Conclusions:1. The abnormal changes of gray matter density of hand-motor related areas in brain are features of secondary injury in patients after stroke. It may have a bad effect on the recovery of hand-motor function.2. The core mechanism of recovery of hand-motor in patients after accepting therapies may be relate with the dynamic change of activations in brain.3. The combination of VBM and ReHo in rs-fMRI may play a potential role in probing the underlying mechanism of brain reorganization and hand motor recovery in patients after subcortical stroke.